Charges have been laid against a charter company and a skipper following the tragic death of a 25-year-old who fell overboard.

Danielle Tamarua fell into the water near Rangitoto Island during a staff party on board a Zefiro Charters Ltd (ZCL) vessel in the Waitematā Harbour in April 2021.

The organisation has been charged by Maritime New Zealand under the Health and Safety Act with failing to comply with its duty to not put others at risk, and that it exposed any individual to risk of death or serious injury.

Specifically, the charge sheet said it was it was "reasonably practicable" for ZCL to provide crew with adequate training to ensure the Maritime Transport Operator Plan was implemented, and so that passengers were prevented from being on the bow of the vessel while under way.

"And/or Monitor and supervise crew to ensure the MOP was implemented; and/or provide adequate signage or barriers to prevent passengers' access to the vessel's bow," the charge sheet said.

The need to manage risks and apply appropriate control measures in relation to "bring your own" alcohol events on board the vessel was also noted.

The maximum penalty for this charge is a $1.5 million dollar fine.

A skipper has also been charged with causing or permitting an act to be done on the ship which causes unnecessary danger or risk to any other person or to any property.

This related to the skipper allegedly permitting passengers to be on the bow of the vessel while it was underway.

This charge carries a maximum penalty of 12 months imprisonment or a fine not exceeding $10,000.

As well as this, he is charged with operating, maintaining or servicing any ship without holding the appropriate current maritime document, allegedly without a current medical certificate.

This carries the same penalty as his first charge.

Zefiro has also been charged with allowing the ship to operate without prescribed qualified personnel, again in relation to the skipper allegedly not having a current medical certificate.

There's a $100,000 maximum penalty for this charge.

Both Maritime New Zealand and Zefiro have been approached for comment.

At the time of Tamarua's death, LittleWolf Catering general manager Marcel Leydesdorff said staff were deeply distressed over the tragedy.

"Danielle Tamarua was a beautiful, kind and much loved member of our team."

Earlier this year police told the Herald their investigation has been completed and no criminal charges were laid.

"The police investigation has been completed in relation to this matter with no criminal charges laid. The matter has been referred to the Coroner."

Staff of Shallot Hospitality, trading as LittleWolf Catering, were the guests on board the boat at the time.

Two men had jumped into the harbour in a bid to save the 25-year-old but she was brought back to the vessel unresponsive, a witness told the Herald at the time.

LittleWolf established a Givealittle page for Tamarua's partner and two young children, and more than $32,000 was raised.

"Danielle's passing is a huge loss to her young family," Leydesorff wrote on the page.

"Danielle left us on April 1st, after suffering a tragic accident at our staff party, surrounded by her colleagues and work friends."

He described Tamarua as "talented young chef" and "much loved member" of the kitchen team.

The 25-year-old trained as a chef at hospitality education provider NZMA in Grafton and had worked at various restaurants around Auckland.